A meteorological station recorded the total rainfall for the first six months of the year, as shown in the line graph below. Estimate the total rainfall for January and February.

A meteorological station recorded the total rainfall for the first six months of the year, as shown in the line graph below. How much rainfall was recorded in March?

A meteorological station recorded the total rainfall for the first six months of the year, as shown in the line graph below. Approximately how many more mm of rainfall were recorded in April than February?

A meteorological station recorded the total rainfall for the first six months of the year, as shown in the line graph below. Approximately how many less mm of rainfall were recorded in May than June?

The graph below compares the monthly sales of two bookstores during the first four months of the year. What were the sales of River Books in February?

The graph below compares the monthly sales of two bookstores during the first four months of the year. How much greater were Maple Books' sales than River Books' sales in April?

The graph below compares the monthly sales of two bookstores during the first four months of the year. What was the combined sales of both bookstores in January?